The NTSB’s Aaron Sauer, who is leading the probe, says it could take six to nine months to determine the cause.

Thursday morning, Sauer and other investigators examined the wreckage, which still sat against a light pole on the edge of the BP gas station at Long and Chesterfield Airport roads. The cockpit was completely charred, however, the engine compartment was mostly intact.

Sauer says the condition of the engine, and pictures taken by bystanders, will help investigators.

“Even though the aircraft did sustain quite a bit of fire damage, we did get a lot of first-hand photograph imagery come in, as far as where the fire was contained to, where did it spread to.”

An investigator studies the wreckage of the plane that crashed in Chesterfield Wednesday. (Brian Kelly/KMOX)

After the initial examination on site, the wreckage will be moved to a facility in Tennessee where it can be examined in a controlled environment.

Sauer says despite earlier reports that Smith was flying in from Albuquerque, New Mexico, he actually took off from Deer Valley Airport in north Phoenix, Arizona.

He was on final approach to Spirit of St. Louis Airport when he reported engine trouble. In his last transmission, Smith told the tower he wasn’t sure if he was going to make it to the runway.

Sauer says Smith was an experienced pilot, who as of last year, had over 3,400 hours in the air. He says despite losing his own life, Smith saved lives by crashing the plane where he did.

“As far as being able to put the aircraft down like he did, a tremendous job on his part.”

The plane he was flying, a Beechcraft Bonanza, is a popular model, according to Sauer. The one that crashed was built in 2001, which he says, is “fairly new” in general aviation circles.

Smith was a developer who is credited for leading the redevelopment of the Chase Park Plaza Hotel in the 1990s.